The present invention relates to an electromagnetic contactor for establishing and interrupting the main power supply circuit of factories or a power supply circuit for a large-scale motor.
A conventional two-contact three-phase electromagnetic contactor employs an integrally formed three-phase crossbar which is movably provided for holding a movable core, wherein the motion of the crossbar is limited by the gap defined by the base plate fixedly mounted to hold the crossbar.
Therefore, simultaneous contact of the contacts of the three-phase contactors have been affected by the tilting of the crossbar within said gap. It is possible to perform a sliding adjustment of the crossbar in small-sized electromagnetic contactor within a range of allowance to practically negligible extent. In a large sized one, however, the crossbar having contacts for three phases are invariably formed integrally. As a result, the preciseness of the thus formed crossbar is affected to such an extent that the gap must be enlarged at the risk of expected simultaneous contact of the contacts for three phases due to the enlarged tilting of the crossbar.
The present invention is intended to solve the above problem and its object is to provide a large-sized electromagnetic contactor in which simultaneous contact of the three phase movable and fixed contacts is assured even if the three-phase crossbar is integrally formed.